Rotary pump and peripherally toothed disk therefor



July 4, 1967 3 G. [4mm 3,329,354

ROTARY PUMP AND PERIPHERALLY TOOTHED DISH THEREFOR Filed July 15, 1964 2 Sheets-Sheet l INVENTOR.

650/?6 NE/DL .m e3fem, moss 8r Tneslem July 4, 1967 I NEDL I 3,329,354

ROTARY PUMP AND PERIPHERALLY TOOTHED DISH THEREFOR .Filed July 15, 1964 2 Sheets-Sheet 2 1N VEN TOR. GEORG NE/DL nlestem,

United States Patent 3,329,354 ROTARY PUMP AND PERIPHERALLY TOOTHED DISK THEREFOR Georg Neidl, Uferstrasse 56, Berlin N 65, Germany Filed July 15, 1964, Ser. No. 382,707

Claims priority, application Germany, Sept. 6, 1960, N 18,866; Oct. 21, 1960, N 19,066; Aug. 3, 1961, N 20,408

12 Claims. (Cl. 241-46) ABSTRACT OF THE DISCLOSURE A rotary pump for the concurrent displacement and mastication of fluent materials having a generally planar impeller disk fixed to an axially extending drive shaft and provided with a peripheral array of teeth co-operating with the surrounding Wall of a pump chamber centered on the axis of rotation of the disk to shear the material displaced by the pump, the arrays of teeth along the opposite edges of the disk being provided in respective mutually parallel planes inclined to the shaft. The teeth of the disk are received in circumferential grooves along the inner wall of the pump chamber, the grooves being interrupted to increase the shearing action. The teeth are generally pyramidal with three surfaces, each extending laterally outwardly of the disk edges.

My present invention relates to improvements in rotary pumps for the simultaneous mastication, comminution, homogenization and displacement of viscous materials and those containing a high proportion of solids as described in my US. Patent No. 2,956,503, issued Oct. 18, 1960 and my application Ser. No. 61,934, filed Oct. 11, 1960 and now US. Patent No. 3,120,353, as Well as my copending application Ser. No..134,964, filed Aug. 30, 1961 and now US. Patent No. 3,164,320. The present application is a continuation-in-part of said application Ser. No. 134,964.

In the aforementioned patents, I disclose and claim rotary-pump apparatus wherein the pump or impeller member is generally disk-shaped and is oblique to its axis of rotation in a housing whose pumping chamber is a figure of revolution surrounding this axis, the periphery of the disk being provided with teeth whose function it is to facilitate the comminution, homogenization, kneading, fulling etc. of viscous heterogeneous materials such as sewage, edible substances, pulps, building material and the like. These teeth may co-operate with circumferential grooves in the pump chamber wall into which the teeth may extend or with projections extending into the chamber from this wall.

It is the principal object of the present invention to provide an improved rotary pump of the character described whereby the physical modification of the material to be treated is more effective and efiicient than possible heretofore.

Still another object of this invention is to provide a rotary impeller disk for a pump of the character described whereby homogenization and comminution of the displaced material can be substantially improved.

Prior to discussing the essential features of the present invention in detail, it must be observed that the term pump is used in the present case as an expression of convenience since there exists no conventional succinct description of a device or apparatus which is equally capable of displacement of viscous semisolid or heterogeneous materials normally considered difiicult to pump and of disintegration, homogenization and comminution of materials contained within the treated flow.

It has been found, according to the present invention, that the serrations or teeth formed along the periphery of the impeller disk should generally be arranged in two or more rows, these rows being parallel to the plane of the disk. Moreover, it is an important feature of the invention that the teeth of the impeller disk be of generally pyramidal configuration. Preferably, each individual tooth should be of three-sided shape so that corresponding pyramidal surfaces of the teeth of each row are flush or coplanar with the respective side of the disk. Thus, two edges of each of the pyramidal disks lie in the plane of the respective surface of the disk and form an apex in the corresponding disk planes. When the teeth are of threesided configuration and shaped in the manner described above, they each will have a respective inwardly turned edges of each of the pyramidal disks lie in the plane of the present invention, extends to the plane of the opposite side of the disk.

Although this configuration of the teeth appears complicated, it is in fact comparatively simple to produce as will become more readily apparent hereinafter.

According to a further feature of the present invention, the pump housing is provided with circumferential grooves in the manner described in my earlier patents and application referred to above. Since two rows of disk teeth can be provided, it may be noted that the teeth of each row can be of staggered relationship so that the grooves formed in the cylinder will alternately receive teeth of each row.

The provision of circumferentially directed grooves in the pump housing for the teeth of the impeller disk results in an exceptionally fine comminution of any solids of the fluent material to be pumped and in extraordinarily efiicient homogenization.

The term fluid is used herein to define materials which may be difficult to pump under normal conditions even though this material may not originally contain any free liquid and may be highly viscous, semisolid or have a large proportion of solids.

I have found that the improved comminution effected by the pump according to the present invention is at least in part due to the increased number of edges which can be provided on the pump impeller when the above described tooth configuration is employed. Moreover, a significant part of the resulting improvement appears to be .a consequence of the fact that, despite of the comparatively narrow zone of engagement of the impeller in the grooves of the housing, the particles of the pumped material slide along the inwardly directed oblique faces, i.e. those faces which are inclined to the respective plane of the disk surface. These particles are thus directed toward the adjacent edges of the impeller or the pumpchamber -wall and are there comminuted by impact and tearing action, especially at high speeds of pump rotation.

It has been'found that the improved comminution can be still further enhanced by providing the inner wall of the pump chamber and housing with transverse grooves (i.e. transverse to the circumferential grooves) or channels. At the intersections of the circumferential grooves and transverse (e.g. longitudinal or axial) grooves, additional edges are formed which co-operate with the impeller teeth to further comminute the particles.

It is also contemplated, in accordance with the present invention, to provide further rows of teeth whose flanges are at different angles on the periphery of the disk. The provision of numerous small teeth enables the pump member, when mounted in its housing, to satisfactorily handle fibrous materials such as rags and waste paper, normally considered diflicult to comminute, in only one or a few passes through the pump to yield a homogeneous product.

According to another aspect of the present invention, the large number of teeth along the periphery of the impeller disk can be produced by removably securing the disk on the rotatable hubs or the holders having seating or connecting surfaces with different degrees of inclination to the axis of their rotation. The teeth can then be formed by feeding a cutting tool radially with respect to the axis and displacing the cutting tool by increments determining the pitch of the teeth in the longitudinal (i.e. axial) direction. It may be noted that pumps of this nature have an extraordinarily high efiiciency when equipped with a screw-type feed conveyor for supplying the material to be treated to the pump housing through its axial inlet and that of the screw conveyor. Rotary-pump apparatus of this nature is disclosed and claimed in my copending application referred to above.

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 shows a rotary-pump apparatus according to the present invention;

FIG. 2 is a plan view illustrating a step in the production of an impeller disk suitable for use in the pump of FIG. 1, showing the toothed periphery of the disk and the lathe chuck in which it is machined;

FIG. 3 is a slide-elevational view of the disk of FIG.

FIG. 4 is a view of the disk of FIG. 2 during a further machining step;

FIG. 5 shows the pump disk during the production stage illustrated in FIG. 4 but held in a different lathe position;

FIG. 6 is an enlarged fragmentary view of the periphery of the disk of FIG. 5;

FIG. 7 is an enlarged fragmentary view of the disk viewed in the direction of arrow A of FIG. 5;

FIG. 8 is a view of the disk in the direction of the arrow B of FIG. 7;

FIG. 9 is a plan view of a modified apparatus for the production of an impeller disk; and

FIG. 10 shows another disk adapted to be machined in the apparatus of FIG. 9.

In FIG. 1, I show a pump 10 having a housing forming a cylindrical pump chamber lined with a sleeve 11 whose internal peripheral wall is grooved at 36 to receive the teeth 24 of an impeller disk 12 inclined to the axis of rotation of the shaft. The circumferential grooves 36 are of V-shaped cross-section and each receives a respective tooth 24 of the periphery of the disk, whose bushing 43 is secured to a shaft 13 driven by the motor 14 An elongated outlet 15 is provided in the sleeve 11 and communicates with the flanged outlet fitting 16 of the housing 45. Opening 15 also interrupts the circumferential grooves and represents the longitudinal or transverse grooves mentioned above. The inlet 17 of this housing is provided with a screw conveyor 18 rotatable by means not shown, advantageously including a variable-speed transmission for driving the screw conveyor and the impeller disk at selected speed ratios, as described in my copending application Ser. No. 134,694.

Referring now to FIG. 2, in which I show an apparatus for forming the disk illustrated in FIG. 1 or a disk adapted to be substituted for disk 12 in pump 10, it may be seen that the pump disk 230 is fixed via screws 230' to an oblique seating surface 232 of the hub 231 which is removably affixed to a mandrel 233 by a locking screw 229 for rotation about the axis 239. The other end of the mandrel 233 has a stepped enlargement 234 of the configuration of a stepped pulley. The enlarged portion 234 or disk is clamped between the jaws 235' of a chuck 235, the latter being mounted in a conventional lathe not further illustrated. A turning tool 236 is carried by the cross-slide and longitudinal carriage of the lathe. In producing the disk, the disk blank 230 is rotated as illustrated in FIG. 9 about the axis 239 while the tool 236 is fed radially inwardly (arrow C) so as to cut the pair of recesses 237 (FIG. 10) in the peripheral edges of the disk. The disk 230 is mounted at this time in the same position as it will be carried by the shaft of the rotary pump. This pair of recesses lies on a chord of the disk, this chord corresponding to a diameter of the figure of revolution generated by the periphery of the disk upon rotation about its axis. Thus the chord is perpendicular to the axis of rotation 239.

After cutting the first pair of recesses 237, the cutting tool 236 moves by a distance of one tooth in the longitudinal direction (arrow D) and again advances radially in the direction of arrow C until the adjacent set of recesses or teeth is produced. After finishing all of the recesses and partially formed teeth 240 as shown in FIG. 3, the screws 229 and 230' are released to detach the disk 230 from its hub 231, the latter having been removed together with the mandrel 233 from the chuck 235. The disk 230 can then be rotated through an angle of 180 about its axis 230" with respect to the hub 231 and again affixed to the latter via screws 230' while the hub is again attached to the shaft or mandrel 233 via screw 229. The effect of this operation is to rotate the disk 230 through an angle of with respect to the cutting tool 236 about an axis perpendicular to the axes 230" and 239, so that the mandrel 233 and the hub axis 248 run from back to front as illustrated in FIG. 4 instead of from left to right as in FIG. 2 for the same position of the impeller disk as illustrated in this figure. When the mandrel is again mounted in the chuck 235 (FIG. 5), cutting with tool 36 can proceed in the identical manner described above.

The resulting teeth are illustrated in FIGS. 68 and can be seen to be provided in two rows having the configuration of three-sided pyramids. These two rows of teeth 241 and 242 have corresponding relatively remote faces 243 in respective planes of faces 244 and 245 of the disk. The two other sides 246 of the pyramidal teeth obliquely converge toward one another from the respective face 243 and terminate in edges 247 extending from the apex of each tooth in the respective plane 244 or 245 to the base of the tooth at the other plane. The oblique sides 246 have the advantage that, during rotation of the pump disk in the housing (FIG. 1) coarse portions or particles of the material to be treated contact the oblique faces and are pushed relatively inwardly to the inner edges of the teeth; thus there is little likelihood that these particles will leave the cutting regions of the disk before they are sufficiently comminuted. It is also possible to provide cutting tools similar to that shown at 236 whose profiles are different from the V-profile of this type. Thus other tooth configurations can be produced; it may also be desirable to dispose the tool so that it is not perpendicular to the longitudinal axis (FIGS. 2 and 5) but is relatively oblique with respect to the latter and in this manner produce different sides which are, however, uniform.

Referring now to FIGS. 9 and 10, it may be seen that the teeth 248 can be first mounted upon a finishing hub 249 whose disk-engaging surface 250 forms an angle a with the axis 251 of the hub. A counterhub 252 is fixed to the opposite side of disk 248 and has an engagement face 253 including the same angle a with the axis. The hubs are provided with mandrels 254, 255 whose extremities are countersunk in the usual manner for mounting in the centers 256, 257 of the lathe. The cutting tool 258 is mounted upon a cross-slide and longitudinal carriage as described above with reference to tool 236 and is moved incrementally by a distance of the pitch of the teeth. Again, the disk is rotated through an angle of 90 for cutting in the opposite direction.

From FIG. 10 it may be seen that a second set of hubs 259, 260, can be afiixed to the pump disk 248, these hubs having abutment faces 261 and 262 which include a larger angle b with the hub axis 263. When this set of hubs is used subsequently, another array of teeth is produced as previously described. Through the use of several sets of hubs with different angles in succession, it is possible to obtain any desired division and fineness of teeth.

The invention as described and illustrated is believed to admit of many modifications and variations within the ability of persons skilled in the art, all such modifications and variations being deemed to be included within the spirit and scope of the appended claims.

I claim:

1. A rotary pump for the displacement and mastication of fluent materials, comprising a pump housing forming a pump chamber constituting a figure of revolution centered upon an axis, said housing having a generally axial inlet for said material and at least one generally radial outlet opening into said chamber; and a generally fiat impeller disk journaled in said chamber at an inclination to said axis and rotatable therearound with opposite peripheral edges of said disk sweeping along the wall of said chamber, said peripheral edges being each provided with a plurality of arrays of teeth lying in respective planes parallel to said disk.

2. A rotary pump as defined in claim 1, wherein said wall of said chamber is formed with circumferential grooves each receiving one tooth of each of said peripheral edges of said disk.

3. A rotary pump as defined in claim 2, wherein said circumferential grooves are interrupted at least once in the direction of rotation of said disk.

4. A rotary pump as defined in claim 1, wherein the teeth of adjacent arrays of each of said peripheral edges are longitudinally staggered relative to one another.

5. A rotary pump as defined in claim 1, wherein two of said arrays of teeth are provided along each of said peripheral edges of said disk, said disk having generally planar faces, the teeth of each array having apices lying in respective planes of the faces of said disk.

6. A rotary pump as defined in claim 5, wherein each of said teeth is of generally pyramidal configuration with three surfaces extending laterally outwardly of said edges of said disk.

7. A rotary pump as defined in claim 6, wherein one of said surfaces of each of said teeth is coplanar with a respective face of said disk and the other two of said surfaces are inclined toward one another and define an inner edge extending between the planes of the faces of said disk.

8. An impeller for an inclined-disk rotary pump, said impeller comprising a drive shaft, and a generally fiat disk fixed obliquely on said shaft and having a pair of opposite peripheral edges adapted to sweep along the wall of a pumping chamber, said peripheral edges being each provided with a plurality of arrays of teeth lying in respective planes parallel to said disk and inclined to said shaft.

9. An impeller as defined in claim 5, wherein the teeth of adjacent arrays of each of said peripheral edges are longitudinally staggered relative to one another.

10. An impeller as defined in claim 9, wherein two of said arrays of teeth are provided along each of said peripheral edges of said disk, said disk having generally planar faces, the teeth of each array having apices lying in respective planes of the faces of said disk.

11. An impeller as defined in claim 10, wherein each of said teeth is of generally pyramidal configuration with three surfaces extending laterally outwardly of said edges of said disk.

12. An impeller as defined in claim 11, wherein one of said surfaces of each of said teeth is coplanar with a respective face of said disk and the other two of said surfaces are inclined toward one another and define an inner edge extending between the planes of the faces of said disk.

References Cited UNITED STATES PATENTS 1,944,580 1/1934 Sigoda 89-918 XR 1,989,596 1/1935 Horn 83918 XR 2,072,710 3/1937 Crane 241255 XR 2,117,586 5/1938 Willson 143133 2,336,798 12/1943 Nash 241- XR 2,956,503 10/1960 Neidl 103103 WILLIAM W. DYER, JR., Primary Examiner.

H. F. PEPPER, Assistant Examiner. 

1. A ROTARY PUMP FOR THE DISPLACEMENT AND MASTICATION OF FLUENT MATERIALS, COMPRISING A PUMP HOUSING FORMING A PUMP CHAMBER CONSTITUTING A FIGURE OF REVOLUTION CENTERED UPON AN AXIS, SAID HOUSING HAVING A GENERALLY AXIAL INLET FOR SAID MATERIAL AT LEAST ONE GENERALLY RADIAL OUTLET OPENING INTO SAID CHAMBER; AND A GENERALLY FLAT IMPELLER DISK JOURNALED IN SAID CHAMBER AT AN INCLINATION TO SAID AXIS AND ROTATABLE THEREAROUND WITH OPPOSITE PERIPHERAL EDGES OF SAID DISK SWEEPING ALONG THE WALL OF SAID CHAMBER, SAID PERIPHERAL EDGES BEING EACH PROVIDED WITH A PLURALITY OF ARRAYS OF TEETH LYING IN RESPECTIVE PLANES PARALLEL TO SAID DISK. 